SM2-Threaded Irises

Lever or Ring Actuated
Ø25 mm (Ø0.98") Maximum Aperture
SM2 Threading for Lens Tube Compatibility

SM2D25

Lever-Actuated Iris

SM2D25D

Ring-Actuated Iris

Application Idea

SM2D25D Iris Shown Threaded into
SM2L30 Lens Tube and Mounted in
SM2RC Slip Ring on Ø1/2" Post

Please Wait

Overview
Threading Specs
Feedback

Click to Enlarge
SM2D25D Mechanical Diagram

Click to Enlarge
SM2D25 Mechanical Diagram

SM-Threaded Irises
SM05
SM1
SM2
SM3

Features

Lever or Ring Aperture Control
SM2 (2.035"-40) Internally and Externally Threaded
Minimum Aperture: Ø1 mm (Ø0.04")
Maximum Aperture: Ø25 mm (Ø0.98")

Our SM2 (2.035"-40) threaded irises are compatible with our Ø2" lens tubes and other SM2-threaded components. Each iris has internal SM threading on one side and external SM threading on the other side. The individual black spring steel leaves pivot within the outer ring of the iris and are designed for long-lasting performance over several thousand cycles.

The SM2D25D ring-actuated iris is designed for integration into a 60 mm cage assembly, where the movement of a lever actuated iris would be hampered by the cage rods. This iris also features a locking setscrew with a 0.05" (1.3 mm) hex for locking the ring during installation or removal. Thorlabs also offers the LCP50S Iris for 60 mm Cage Systems which is integrated into a cage plate for direct mounting to cage rods.

Thorlabs' Threading Specifications

Thorlabs' lens tubes utilize a series of non-standard threadings. Threading specifications are given below for our SM threadings utilized in our lens tube and cage system components so that you can machine mating components to suit your application. We also offer products with C-Mount and RMS threadings, and the specifications for these threadings are also given below. Please note that other manufacturers may have different tolerances for these threads. For other thread specifications that are not listed here, please contact Tech Support.

Click to Enlarge

SM05 Threading: Ø1/2" Lens Tubes, 16 mm Cage Systems
External Thread, 0.535"-40.0, UNS-2A		Internal Thread, 0.535"-40.0, UNS-2B
Max Major Diameter	0.5340"	Min Major Diameter	0.5350"
Min Major Diameter	0.5289"	Min Pitch Diameter	0.5188"
Max Pitch Diameter	0.5178"	Max Pitch Diameter	0.5230"
Min Pitch Diameter	0.5146"	Min Minor Diameter (and 83.3% of thread)	0.508"
Max Minor Diameter	0.5069"	Max Minor Diameter (and 64.9% of thread)	0.514"

RMS Threading: Objective, Scan, and Tube Lenses
External Thread, 0.800"-36.0, UNS-2A		Internal Thread, 0.800"-36.0, UNS-2B
Max Major Diameter	0.7989"	Min Major Diameter	0.8000"
Min Major Diameter	0.7934"	Min Pitch Diameter	0.7820"
Max Pitch Diameter	0.7809"	Max Pitch Diameter	0.7866"
Min Pitch Diameter	0.7774"	Min Minor Diameter (and 83.3% of thread)	0.770"
Max Minor Diameter	0.7688"	Max Minor Diameter (and 64.9% of thread)	0.777"

C-Mount Threading: Machine Vision Lenses, CCD/CMOS Cameras
External Thread, 1.000"-32.0, UN-2A		Internal Thread, 1.000"-32.0, UN-2B
Max Major Diameter	0.9989"	Min Major Diameter	1.0000"
Min Major Diameter	0.9929"	Min Pitch Diameter	0.9797"
Max Pitch Diameter	0.9786"	Max Pitch Diameter	0.9846"
Min Pitch Diameter	0.9748"	Min Minor Diameter (and 83.3% of thread)	0.966"
Max Minor Diameter	0.9651"	Max Minor Diameter (and 64.9% of thread)	0.974"

SM1 Threading: Ø1" Lens Tubes, 30 mm Cage Systems
External Thread, 1.035"-40.0, UNS-2A		Internal Thread, 1.035"-40.0, UNS-2B
Max Major Diameter	1.0339"	Min Major Diameter	1.0350"
Min Major Diameter	1.0288"	Min Pitch Diameter	1.0188"
Max Pitch Diameter	1.0177"	Max Pitch Diameter	1.0234"
Min Pitch Diameter	1.0142"	Min Minor Diameter (and 83.3% of thread)	1.008"
Max Minor Diameter	1.0068"	Max Minor Diameter (and 64.9% of thread)	1.014"

SM30 Threading: Ø30 mm Lens Tubes
External Thread, M30.5x0.5		Internal Thread, M30.5x0.5
Max Major Diameter	30.480 mm	Min Major Diameter	30.500 mm
Min Major Diameter	30.371 mm	Min Pitch Diameter	30.175 mm
Max Pitch Diameter	30.155 mm	Max Pitch Diameter	30.302 mm
Min Pitch Diameter	30.059 mm	Min Minor Diameter (and 83.3% of thread)	29.959 mm
Max Minor Diameter	29.938 mm	Max Minor Diameter (and 64.9% of thread)	30.094 mm

SM1.5 Threading: Ø1.5" Lens Tubes
External Thread, 1.535"-40, UNS-2A		Internal Thread, 1.535"-40, UNS-2B
Max Major Diameter	1.5339"	Min Major Diameter	1.535"
Min Major Diameter	1.5288"	Min Pitch Diameter	1.5188"
Max Pitch Diameter	1.5177"	Max Pitch Diameter	1.5236"
Min Pitch Diameter	1.5140"	Min Minor Diameter (and 83.3% of thread)	1.508"
Max Minor Diameter	1.5068"	Max Minor Diameter (and 64.9% of thread)	1.514"

SM2 Threading: Ø2" Lens Tubes, 60 mm Cage Systems
External Thread, 2.035"-40.0, UNS-2A		Internal Thread, 2.035"-40.0, UNS-2B
Max Major Diameter	2.0338"	Min Major Diameter	2.0350"
Min Major Diameter	2.0287"	Min Pitch Diameter	2.0188"
Max Pitch Diameter	2.0176"	Max Pitch Diameter	2.0239"
Min Pitch Diameter	2.0137"	Min Minor Diameter (and 83.3% of thread)	2.008"
Max Minor Diameter	2.0067"	Max Minor Diameter (and 64.9% of thread)	2.014"

SM3 Threading: Ø3" Lens Tubes
External Thread, 3.035"-40.0, UNS-2A		Internal Thread, 3.035"-40.0, UNS-2B
Max Major Diameter	3.0337"	Min Major Diameter	3.0350"
Min Major Diameter	3.0286"	Min Pitch Diameter	3.0188"
Max Pitch Diameter	3.0175"	Max Pitch Diameter	3.0242"
Min Pitch Diameter	3.0133"	Min Minor Diameter (and 83.3% of thread)	3.008"
Max Minor Diameter	3.0066"	Max Minor Diameter (and 64.9% of thread)	3.014"

Posted Comments:
No Comments Posted